22 ROCHESTER ACADEMY OF SCIENCE. [ Nov. 11, 
A curious feature noted when the auroras fail to appear, or are very 
faint, Is an evident increase in the violence and extent of thunderstorms, 
as though they had taken the place of the auroras. 
Tabulating observations of auroras so as to show their extent and 
distribution in- periods of twenty-seven days, and tabulating in like 
manner magnetic perturbations so as to show their distribution in periods 
of six hundred and forty-eight hours, it becomes possible to determine 
at a glance the relative productiveness of different sections of the sun 
in relation to these phenomena. Such tabulation also affords a basis 
for comparisons in regard to manifestations of the forces concerned, 
other than the aurora. As has been indicated, it is possible that thun- 
derstorms may be a reciprocal or alternative method of manifestation 
of forces, which under other conditions find their expression in the 
aurora. Systematic observation in regard to this point, upon a suffi- 
ciently extensive scale, may lead to results of the highest interest. At 
the time of the long series of earthquakes at Charleston and vicinity in 
1886, there was manifest a periodic increase in the severity of the 
shocks, which seemed to indicate that magnetic induction from the sun 
might be concerned to some extent at least in the production of earth- 
quake shocks in localities where the pre-existing conditions are thus 
favorable. The same peculiarity was noted in connection with the 
Riviera earthquake, and has led to much discussion among European 
scientists. Such comparisons as the writer has been able to make indi- 
cate that the conditions favorable to increase of auroras may be favor- 
able also to increase of earthquakes, but other conditions as well must 
be taken into the account. For example, the violent earthquake shocks 
in the Mississippi Valley, coincident with the total destruction of 
Caraccas, South America, in 1811, occurred at a time when sun spots, 
auroras and magnetic storms were at a very decided minimum. Hence 
in this case magnetic induction, or the conditions originating it, could 
have played but little part. 
There are certain facts in connection with meteorology that point 
to the influence of forces of cosmical origin and variable nature. The 
International Daily Weather Charts show, for example, that at times the 
barometer fluctuates, within twenty-four hours, in precisely the same 
way, at all centers of high and low barometer, as though some impulse 
had been imparted to the entire atmosphere. In like manner extreme 
weather conditions of every sort have not unfrequently been observed to 
be of world wide extent. At the time of the “ New York Blizzard” a 
series of phenomenal wind storms belted the entire earth. In 1877 and 
1878, continents, islands and seas everywhere throughout the equatorial 
KS 
